[Info-vax] wrong file format

Hein RMS van den Heuvel heinvandenheuvel at gmail.com
Sun Jan 3 15:13:40 EST 2021


On Saturday, January 2, 2021 at 11:01:12 PM UTC-5, Craig A. Berry wrote:
> On 1/2/21 8:04 PM, Arne Vajhøj wrote: 
> > On 12/31/2020 10:54 PM, Bill Gunshannon wrote: 

> > * the traditional story is that all language RTL IO goes 
> > through RMS - including C RTL (even though that one 
> > supposedly is a bit more complicated than other 
> > languages) 

Last century, yes. 
Today for the simple sequential file COBRTL, CRTL and SORT switched away from record IO to roll their own with BlockIO ($READ, $WRITE).
I don't recall them doing direct $QIO calls. BlockIO is a tiny layer over QIO adding error handling mostly.
Record IO is way to expensive for high volume IO - going in and out of exec mode 'all the time', probing the argument blocks and buffers and so on. 
Block IO incurs this overhead typically much less frequently to the point where it does not really matter ( 10 ...  50 times less is my guess).

It's all easy enough to verify for your exact situation with a tiny program doing the IO calls you would like to understand.
Code in a pause after a few IOs and activate ANALYZE /SYSTEM ... SET PROC ... SHOW PROC/RMS=(RAB,FAB,BDBSUM[,IFAB,IRAB,FSB])

Hein



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